[FIXED] Pandas sample with weights

Issue

I have df and I'd like to make some sampling from it with respect to distribution of some variable. Let's say df['type'].value_counts(normalize=True) returns:

A 0.3
B 0.5
C 0.2

I'd like to make something like sampledf = df.sample(weights=df['type'].value_counts(normalize=True)) such that sampledf ['type'].value_counts(normalize=True) will return almost the same distridution. How to pass dict with frequency here?

Solution

Weights has to take a series of the same length as the original df, so best is to add it as a column:

df['freq'] = df.groupby('type')['type'].transform('count')
sampledf = df.sample(weights = df.freq)

Or without adding the column:

sampledf = df.sample(weights = df.groupby('type')['type'].transform('count'))

Answered By - Josh Friedlander